Before the introduction of long term evolution (LTE) or Internet protocol (IP) multimedia subsystem or IP multimedia core network subsystem (IMS) technology, a format of a message transmitted from an electronic device such as a smart phone may comply, in general, with a standard defined at a circuit switching (CS) network. For example, in the case where the CS network is a code division multiple access (CDMA) network, the message format may be determined according to the 3rd Generation Partnership Project 2 (3GPP2) communication standard; in the case where the CS network is a global system for mobile communications (GSM network), the message format may be determined according to the 3GPP communication standard.
As a global model of the electronic device such as the smart phone is released and an LTE network is constructed, a short service message (SMS) over IMS service using the IMS or a (SG-SMS) (SMS with LTE) using the LTE network as well as an SMS using a CS network of the related art may be possible.
As described above, a method for transmitting a message through an LTE network may include “SMS over IMS” for transmitting the message in SG-SMS through a control channel of the LTE network or for transmitting the message in session initiation protocol (SIP) through the IMS. A compatibility problem may occur if an electronic device supporting the IMS transmits and receives a message in compliance with the 3GPP2 in the CS network and transmits and receives a message in compliance with the 3GPP in the packet switching (PS) network.
Furthermore, an electronic device of a CDMA provider such as Verizon, KDDI, Sprint, or the like may support the SMS over IMS and may provide a GSM roaming service at a roaming situation (e.g., in the case where a terminal of the provider is in an European area). In the roaming situation, the electronic device may only connect to an LTE network (i.e., a PS network) at a circuit switched fall-back (CSFB) network environment. However, it may be impossible to know information of the CS network using information of the PS network, thereby making it impossible for the electronic device to determine an SMS format using the CS network. In this case, the electronic device (i.e., a CDMA provider terminal) may transmits a message according to the CDMA format (3GPP2), and transmitting of a message may fail in a situation where roaming is made in the GSM network CS.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.